The invention relates to acoustic systems, and more particularly to an acoustic system including a chamber having an input for receiving an input acoustic wave and guiding the input acoustic wave along a flowpath to a chamber output, and an acoustic transducer interacting with the acoustic wave in the chamber.
The invention arose during continuing development efforts relating to the subject matter shown and described in U.S. Pat. Nos. 4,665,549, 4,677,676, 4,677,677, 4,736,431, 4,815,139, 4,837,834, incorporated herein by reference. The patents show various active acoustic attenuation systems. Active acoustic attenuation is accomplished by sound wave interference. Undesirable noise is attenuated by the introduction of canceling sound which ideally is a mirror image of the undesirable sound, to thus cancel same. The present invention is applicable to active attenuation and other acoustic systems.
The present invention provides a venturi for cooling and/or cleaning an acoustic transducer such as a microphone or a canceling loudspeaker. The invention provides various chamber and venturi structures in combination.
Mufflers with venturis are known in the prior art, for example U.S. Pat. Nos. 4,487,289 and 4,697,668.